Sequential Sectioning of the Ulnar Collateral Ligament of the Elbow in Cadaveric Arms with Ulnohumeral Laxity Assessed by Dynamic Ultrasonography

Objectives: Injury of the ulnar collateral ligament (UCL), whether acute or chronic, is potentially career-threatening for elite overhead throwing athletes. Dynamic ultrasound (DUS) allows for rapid, cost-effective, non-invasive, and non-radiating evaluation of the UCL and elbow joint both at rest and with applied stress. The purpose of this study was to determine the amount of cadaveric elbow valgus laxity with sequential UCL sectioning using DUS. Our objective was to quantify which portions of the UCL must be injured to cause the varying levels of laxity seen clinically on DUS testing. No prior study has used DUS to quantify valgus joint laxity with sequential cadaveric UCL sectioning. It was hypothesized that the change in laxity due to release of the anterior band of the UCL would be greater than that seen when the posterior and transverse bands were cut. Methods: Twelve cadaveric elbows were dissected free of skin and subcutaneous tissue by an experienced orthopaedic surgeon. Baseline DUS at rest and with applied valgus stress was then performed by an experienced ultrasonographer. Sequential sectioning of the medial elbow soft-tissue stabilizing structures was then carried out with valgus stress applied to the joint at each sectioning interval utilizing a standardized device (Telos, Marburg, Germany). First the transverse band of the UCL was released, followed by the posterior band, then the anterior bundle of the anterior band, the remaining posterior bundle of the anterior band, and finally the complete flexor pronator mass. Results: Mean ulnohumeral laxity in millimeters with 95% CIs was calculated for each step of the sequence. The deltas between each step of the dissection were also calculated with means and 95% CIs. Mean baseline laxity of the unstressed ulnohumeral joint at rest was 3.2 mm (CI, 2.2-4.2); with the addition of valgus stress, mean laxity was 4.7 mm (CI, 3.5-6.0). When the transverse band was cut, ulnohumeral laxity increased to a mean of 5.5 mm (CI, 4.0-7.0). With release of the posterior band, mean laxity was 6.4 mm (CI, 4.3-8.5). When the anterior bundle of the anterior band of the UCL was cut, mean ulnohumeral laxity was 8.4 mm (CI, 5.7-11.0) and when the entire anterior band was released, mean laxity was 10.9 mm (CI, 7.8-14.0). Complete release of the flexor pronator muscle mass resulted in mean ulnohumeral laxity of 15.5 mm (CI, 12.9-18.1). The largest deltas were observed with release of the anterior bundle of the anterior band (2.0 mm; CI, 1.0-3.0), the entire anterior band (2.6 mm; CI, 1.3-3.8), and flexor pronator mass (4.6 mm; CI, 1.3-3.8). Release of the transverse and posterior bands of the UCL resulted in deltas of 0.74 mm (CI, 0.1-1.3) and 0.9 mm (CI, 0.3-1.5) respectively. Conclusion: DUS allows for rapid, cost-effective, non-invasive, non-radiating evaluation of the elbow joint and UCL both at rest and with applied valgus stress. Previous studies have indicated that DUS can identify abnormalities of the UCL associated with chronic degeneration and ligamentous injury including thickening of the anterior band of the UCL as well as hypoechoic foci/calcifications. The results of the current cadaveric study suggest that different changes in clinical laxity are seen on DUS with injury of particular bands of the UCL. Early identification and localization of injury to a particular band of the UCL may allow more appropriate selection of patients who will benefit from operative treatment. © The Author(s) 2013

Youth Single-Sport Specialization in Professional Baseball Players.

Background: An increasing number of youth baseball athletes are specializing in playing baseball at younger ages. Purpose: The purpose of our study was to describe the age and prevalence of single-sport specialization in a cohort of current professional baseball athletes. In addition, we sought to understand the trends surrounding single-sport specialization in professional baseball players raised within and outside the United States (US). Study Design: Cross-sectional study; Level of evidence, 3. Methods: A survey was distributed to male professional baseball athletes via individual team athletic trainers. Athletes were asked if and at what age they had chosen to specialize in playing baseball at the exclusion of other sports, and data were then collected pertaining to this decision. We analyzed the rate and age of specialization, the reasons for specialization, and the athlete\u27s perception of injuries related to specialization. Results: A total of 1673 professional baseball athletes completed the survey, representing 26 of the 30 Major League Baseball (MLB) organizations. Less than half (44.5%) of professional athletes specialized in playing a single sport during their childhood/adolescence. Those who reported specializing in their youth did so at a mean age of 14.09 ± 2.79 years. MLB players who grew up outside the US specialized at a significantly earlier age than MLB players native to the US (12.30 ± 3.07 vs 14.89 ± 2.24 years, respectively; Conclusion: This study challenges the current trends toward early youth sport specialization, finding that the majority of professional baseball athletes studied did not specialize as youth and that those who did specialize did so at a mean age of 14 years. With the potential cumulative effects of pitching and overhead throwing on an athlete\u27s arm, the trend identified in this study toward earlier specialization within baseball is concerning

Management of Elbow Dislocations in the National Football League.

Background: Although much literature exists regarding the treatment and management of elbow dislocations in the general population, little information is available regarding management in the athletic population. Furthermore, no literature is available regarding the postinjury treatment and timing of return to play in the contact or professional athlete. Purpose: To review the clinical course of elbow dislocations in professional football players and determine the timing of return to full participation. Study Design: Case series; Level of evidence, 4. Methods: All National Football League (NFL) athletes with elbow dislocations from 2000 through 2011 who returned to play during the season were identified from the NFL Injury Surveillance System (NFL ISS). Roster position, player activity, use of external bracing, and clinical course were reviewed. Mean number of days lost until full return to play was determined for players with elbow dislocations who returned in the same season. Results: From 2000 to 2011, a total of 62 elbow dislocations out of 35,324 injuries were recorded (0.17%); 40 (64.5%) dislocations occurred in defensive players, 12 (19.4%) were in offensive players; and 10 (16.1%) were during special teams play. Over half of the injuries (33/62, 53.2%) were sustained while tackling, and 4 (6.5%) patients required surgery. A total of 47 (75.8%) players who sustained this injury were able to return in the same season. For this group, the mean number of days lost in players treated conservatively (45/47) was 25.1 days (median, 23.0 days; range, 0.0-118 days), while that for players treated operatively (2/47) was 46.5 days (median, 46.5 days; range, 29-64 days). Mean return to play based on player position was 25.8 days for defensive players (n = 28; median, 21.5 days; range, 3.0-118 days), 24.1 days for offensive players (n = 11; median, 19 days; range, 2.0-59 days), and 25.6 days for special teams players (n = 8; median, 25.5 days; range, 0-44 days). Conclusion: Elbow dislocations comprise less than a half of a percent of all injuries sustained in the NFL. Most injuries occur during the act of tackling, with the majority of injured athletes playing a defensive position. Players treated nonoperatively missed a mean of 25.1 days, whereas those managed operatively missed a mean of 46.5 days

Aseptically processed and chemically sterilized BTB allografts for anterior cruciate ligament reconstruction: a prospective randomized study.

PURPOSE: To compare the clinical outcomes of bone-patellar tendon-bone (BTB) allografts processed via a novel sterilization system with the traditional aseptically processed BTB allografts for anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 67 patients undergoing ACL reconstruction at 6 independent investigation sites were randomized into one of two intervention groups, BioCleanse-sterilized or aseptic BTB allografts. Inclusion criteria included an acute, isolated, unilateral ACL tear, and exclusion criteria included prior ACL injury, multi-ligament reconstruction, and signs of degenerative joint disease. Post-op examiners and patients were blinded to graft type. Patients were evaluated at 6, 12, and 24 months. Clinical outcomes were compared using the IKDC, a KT-1000 knee arthrometer, level of effusion, and ranges of motion (ROM). RESULTS: After randomization, 24 patients received aseptic BTB allografts and 43 patients received BioCleanse-sterilized allografts. Significant improvement in IKDC scores (P \u3c 0.0001) as well as KT-1000 results (P \u3c 0.0001) was noted over the 24-month period for both groups. IKDC or KT-1000 results were not significantly different between groups at any time point. Active flexion ROM significantly improved from pre-op to 24-month follow-up (P \u3c 0.0001) with no difference between groups at any time point. Active extension ROM did not differ significantly between the two groups. CONCLUSIONS: These results indicate that the sterilization process, BioCleanse, did not demonstrate a statistical difference in clinical outcomes for the BTB allograft at 2 years. The BioCleanse process may provide surgeons with allografts clinically similar to aseptically processed allograft tissue with the benefit of addressing donor-to-recipient disease. LEVEL OF EVIDENCE: II

Kerlan-Jobe Orthopaedic Clinic overhead athlete scores in asymptomatic professional baseball pitchers.

BACKGROUND: The Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow score is a subjective questionnaire that has been validated and been shown to be more specific in overhead athletes than the American Shoulder and Elbow Surgeons scale. The purpose of this study was to determine a mean KJOC score and reasonable range of KJOC scores within which a healthy asymptomatic professional baseball pitcher will fall. It was hypothesized that healthy professional baseball pitchers would have very high KJOC scores. MATERIALS AND METHODS: KJOC questionnaires were given to all healthy pitchers before the start of the season at all levels in 1 professional Minor League system. Pitchers were asked to complete the questionnaire upon reporting to their AAA, AA, or A affiliate team. Any pitcher starting the season on the disabled list was excluded from the study. RESULTS: KJOC scores were returned by 44 pitchers. The mean score for all pitchers was 94.82 (95% confidence interval, 92.94-96.70). The mean score for each question was greater than 9 of 10. The mean score for the AAA affiliate was significantly higher than that for the AA affiliate (P = .015). No other significant differences in scores were found between class levels or groups based on professional playing experience. CONCLUSION: Only 7 of 44 healthy asymptomatic pitchers (16%) had a KJOC score below 90. Therefore, we believe that the KJOC score is an accurate assessment for overhead athletes and normal values should be greater than 90. Anything below this value could be a potential cause for concern for team physicians. LEVEL OF EVIDENCE: Basic Science, Survey Study, Healthy Subjects

Return to School After Anterior Cruciate Ligament Reconstruction: A Prospective Study of Adolescents and Young Adults.

Background: The ability to return to school after orthopaedic surgery is an important consideration for young patients, as there is substantial literature indicating that school attendance is correlated strongly with academic performance. Purpose: To evaluate the time to return to school, the barriers that students encounter when returning to school, and the academic effect of anterior cruciate ligament reconstruction (ACLR) in high school (HS) and college students. Study design: Cohort study; Level of evidence, 2. Methods: Full-time HS and college/graduate school (C/GS) students who underwent ACLR during the 2017 to 2018 and 2018 to 2019 academic periods were included in the study. Patients were contacted 2 weeks postoperatively to complete a questionnaire that assessed their time to return to school and barriers that interfered with their ability to return, and they completed a second questionnaire at 6 weeks postoperatively that assessed academic performance and challenges faced upon returning to school. Results: Included were 36 (52.2%) full-time HS students and 33 (47.8%) full-time C/GS students. HS students reported a longer time to return to school compared with C/GS students (8.51 vs 5.89 days; P = .008). In addition, HS students missed more scheduled school days than C/GS students (5.39 vs 2.90 days; P \u3c .001). The majority of HS (73.5%) and C/GS (65.5%) students cited pain as a barrier to return, and more than half of HS (70.6%) and C/GS (55.2%) students also cited restricted mobility as a barrier to return. HS students were more likely to miss an examination in the early postoperative period compared with their C/GS counterparts (65.7% vs 39.3%; P = .037). Many students in both cohorts received a grade less than expected in the early postoperative period; this was not significantly different between the 2 groups (HS, 50.0%; C/GS, 42.9%; P = .489). Conclusion: ACLR can have a negative effect on school attendance and academic performance among HS and C/GS students. Orthopaedic surgeons should counsel all students and their families adequately about the potential academic effect of orthopaedic surgery in order to maximize clinical results, academic performance, and satisfaction in their patients

Return to play rates after ulnar nerve transposition and decompression surgery: a retrospective analysis.

Background: Medial elbow pain is a common complaint in overhead throwing athletes. The throwing motion places repetitive tensile and compressive forces on the elbow resulting in significant stress across the ulnohumeral joint. This stress can result in soft-tissue, ligamentous, and ulnar nerve injury. The purpose of this study was to retrospectively investigate the clinical findings and outcomes, including return to play rates, of patients who underwent ulnar nerve transposition surgery for isolated ulnar neuritis. Methods: Throwing athletes who underwent isolated, primary ulnar nerve transposition surgery over an eight-year period, 2009 to 2017, were identified and included in our analysis. Nonthrowing athletes, those who underwent revision ulnar nerve transposition surgery, and those who underwent concomitant ulnar collateral ligament reconstruction or repair were excluded. Patients were contacted to complete the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow Score as well as a return to play rate questionnaire. The minimum follow-up was 2 years. Results: Fifteen patients met the inclusion criteria: 13 (86.7%) men and 2 (13.3%) women. The average age at the time of surgery was 19.2 years old (range, 15.6-28.0). Preoperatively, 13 (86.7%) patients played baseball and 2 (13.3%) patients played softball. Two patients (13.3%) underwent a previous ulnar collateral ligament reconstruction. There were no complications. The average final follow-up was 65.26 (range, 24.44-113.29) months with an average Kerlan-Jobe Orthopaedic Clinic Score of 64.51 (range, 28.60-100.00). Thirteen (86.7%) patients were able to return to their preinjury sport, 2 to a higher level of competition, 8 to the same level, and 3 to a lower level. Seven of the 13 (53.8%) patients sustained a postoperative ipsilateral shoulder or elbow injury at an average of 19.57 (range, 7.00-36.00) months postoperatively. All patients reported sustaining the injury as a result of throwing. Conclusion: The results of our study indicate that ulnar nerve transposition surgery in throwing athletes allows athletes to return to throwing with low reoperation rates. However, more than half of the athletes in our analysis sustained a subsequent ipsilateral shoulder or elbow injury. Further investigation regarding outcomes in throwing athletes after ulnar nerve transposition surgery is warranted

Growth of (110) Diamond using pure Dicarbon

We use a density-functional based tight-binding method to study diamond growth steps by depositing dicarbon species onto a hydrogen-free diamond (110) surface. Subsequent C_2 molecules are deposited on an initially clean surface, in the vicinity of a growing adsorbate cluster, and finally, near vacancies just before completion of a full new monolayer. The preferred growth stages arise from C_2n clusters in near ideal lattice positions forming zigzag chains running along the [-110] direction parallel to the surface. The adsorption energies are consistently exothermic by 8--10 eV per C_2, depending on the size of the cluster. The deposition barriers for these processes are in the range of 0.0--0.6 eV. For deposition sites above C_2n clusters the adsorption energies are smaller by 3 eV, but diffusion to more stable positions is feasible. We also perform simulations of the diffusion of C_2 molecules on the surface in the vicinity of existing adsorbate clusters using an augmented Lagrangian penalty method. We find migration barriers in excess of 3 eV on the clean surface, and 0.6--1.0 eV on top of graphene-like adsorbates. The barrier heights and pathways indicate that the growth from gaseous dicarbons proceeds either by direct adsorption onto clean sites or after migration on top of the existing C_2n chains.Comment: 8 Pages, 7 figure

Diagnosis and treatment of medial epicondylitis of the elbow

Epicondylitis is one of the most common elbow problems in adults, occurring both laterally and medially. Medial epicondylitis of the elbow, commonly referred to as ‘‘golfer’s elbow,’ ’ is characterized by pathologic changes to the musculo-tendonous origin at the medial epicondyle. Accurate diagnosis is dependent upon a complete understanding of the anatomic, epidemiologic, and pathophysiologic factors that distinguish epicondylitis from other elbow conditions. Originally described by Henry Morris in 1882 as ‘‘lawn-tennis elbow,’’ epicondylitis has since been studied and written on extensively [1]. Lateral epicondylitis, often labeled ‘‘tennis elbow,’ ’ has received the majority of this attention. There exists, however, a paucity of literature regarding medial epicondylitis, likely due to its infrequent incidence of only 9.8 % to 20 % of all epicondylitis diagnoses [2–4]. Originally thought to be an inflammatory process, as the name suggests, epicondylitis has been shown histologically to result from tendonous microtearing, followed by an incomplete reparative response. Conse-quently, some physicians prefer the more accurate term, tendonosis, when describing elbow epicondylitis. Epidemiology and etiology Medial epicondylitis occurs much less frequently than lateral epicondylitis,Diagnosis and treatment of medial epicondylitis of the elbow Clin Sports Med 23 (2004) 693–705which has been diagnosed seven to ten times more often [5]. Although the syndrome has been identified in patients ranging from 12 to 80 years old, it predominantly occurs in the fourth and fifth decades. Male and female prevalence 0278-5919/04/ $ – see front matter D 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.csm.2004.04.011 * Corresponding author